* [PATCH 0/1] NFS: Fix read_bytes for buffered reads @ 2023-03-09 18:58 Dave Wysochanski 2023-03-09 18:58 ` [PATCH 1/1] NFS: Fix /proc/PID/io " Dave Wysochanski 0 siblings, 1 reply; 3+ messages in thread From: Dave Wysochanski @ 2023-03-09 18:58 UTC (permalink / raw) To: Anna Schumaker, Trond Myklebust, Daire Byrne; +Cc: linux-nfs This patch fixes the read_bytes count for NFS buffered reads. Simple reproducer follows. Before this patch: # mount 127.0.0.1:/ /mnt/nfs # bash # function dump_stats { cat /proc/$$/io; } # trap dump_stats EXIT # cat /mnt/nfs/file1.bin > /dev/null # exit exit rchar: 3587436 wchar: 1054077 syscr: 544 syscw: 33 read_bytes: 0 write_bytes: 0 cancelled_write_bytes: 0 After this patch: # mount 127.0.0.1:/ /mnt/nfs # bash # function dump_stats { cat /proc/$$/io; } # trap dump_stats EXIT # cat /mnt/nfs/file1.bin > /dev/null # exit exit rchar: 3587278 wchar: 1054161 syscr: 544 syscw: 33 read_bytes: 1048576 write_bytes: 0 cancelled_write_bytes: 0 Dave Wysochanski (1): NFS: Fix /proc/PID/io read_bytes for buffered reads fs/nfs/read.c | 3 +++ 1 file changed, 3 insertions(+) -- 2.31.1 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 1/1] NFS: Fix /proc/PID/io read_bytes for buffered reads 2023-03-09 18:58 [PATCH 0/1] NFS: Fix read_bytes for buffered reads Dave Wysochanski @ 2023-03-09 18:58 ` Dave Wysochanski 2023-03-14 20:27 ` Daire Byrne 0 siblings, 1 reply; 3+ messages in thread From: Dave Wysochanski @ 2023-03-09 18:58 UTC (permalink / raw) To: Anna Schumaker, Trond Myklebust, Daire Byrne; +Cc: linux-nfs Prior to commit 8786fde8421c ("Convert NFS from readpages to readahead"), nfs_readpages() used the old mm interface read_cache_pages() which called task_io_account_read() for each NFS page read. After this commit, nfs_readpages() is converted to nfs_readahead(), which now uses the new mm interface readahead_page(). The new interface requires callers to call task_io_account_read() themselves. In addition, to nfs_readahead() task_io_account_read() should also be called from nfs_read_folio(). Fixes: 8786fde8421c ("Convert NFS from readpages to readahead") Link: https://lore.kernel.org/linux-nfs/CAPt2mGNEYUk5u8V4abe=5MM5msZqmvzCVrtCP4Qw1n=gCHCnww@mail.gmail.com/ Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> --- fs/nfs/read.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/nfs/read.c b/fs/nfs/read.c index c380cff4108e..e90988591df4 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -15,6 +15,7 @@ #include <linux/stat.h> #include <linux/mm.h> #include <linux/slab.h> +#include <linux/task_io_accounting_ops.h> #include <linux/pagemap.h> #include <linux/sunrpc/clnt.h> #include <linux/nfs_fs.h> @@ -337,6 +338,7 @@ int nfs_read_folio(struct file *file, struct folio *folio) trace_nfs_aop_readpage(inode, folio); nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); + task_io_account_read(folio_size(folio)); /* * Try to flush any pending writes to the file.. @@ -393,6 +395,7 @@ void nfs_readahead(struct readahead_control *ractl) trace_nfs_aop_readahead(inode, readahead_pos(ractl), nr_pages); nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); + task_io_account_read(readahead_length(ractl)); ret = -ESTALE; if (NFS_STALE(inode)) -- 2.31.1 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 1/1] NFS: Fix /proc/PID/io read_bytes for buffered reads 2023-03-09 18:58 ` [PATCH 1/1] NFS: Fix /proc/PID/io " Dave Wysochanski @ 2023-03-14 20:27 ` Daire Byrne 0 siblings, 0 replies; 3+ messages in thread From: Daire Byrne @ 2023-03-14 20:27 UTC (permalink / raw) To: Dave Wysochanski; +Cc: Anna Schumaker, Trond Myklebust, Daire Byrne, linux-nfs Thanks Dave. I can confirm that this does indeed fix the reporting of /proc/PID/read_bytes for us. I actually applied it (cleanly) to our v5.18 based kernel as we use that in production on our render farm. We use the read_bytes in our post render statistics to help track per render IO. Tested-by: Daire Byrne <daire@dneg.com> On Thu, 9 Mar 2023 at 19:00, Dave Wysochanski <dwysocha@redhat.com> wrote: > > Prior to commit 8786fde8421c ("Convert NFS from readpages to > readahead"), nfs_readpages() used the old mm interface read_cache_pages() > which called task_io_account_read() for each NFS page read. After > this commit, nfs_readpages() is converted to nfs_readahead(), which > now uses the new mm interface readahead_page(). The new interface > requires callers to call task_io_account_read() themselves. > In addition, to nfs_readahead() task_io_account_read() should also > be called from nfs_read_folio(). > > Fixes: 8786fde8421c ("Convert NFS from readpages to readahead") > Link: https://lore.kernel.org/linux-nfs/CAPt2mGNEYUk5u8V4abe=5MM5msZqmvzCVrtCP4Qw1n=gCHCnww@mail.gmail.com/ > Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> > --- > fs/nfs/read.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/nfs/read.c b/fs/nfs/read.c > index c380cff4108e..e90988591df4 100644 > --- a/fs/nfs/read.c > +++ b/fs/nfs/read.c > @@ -15,6 +15,7 @@ > #include <linux/stat.h> > #include <linux/mm.h> > #include <linux/slab.h> > +#include <linux/task_io_accounting_ops.h> > #include <linux/pagemap.h> > #include <linux/sunrpc/clnt.h> > #include <linux/nfs_fs.h> > @@ -337,6 +338,7 @@ int nfs_read_folio(struct file *file, struct folio *folio) > > trace_nfs_aop_readpage(inode, folio); > nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); > + task_io_account_read(folio_size(folio)); > > /* > * Try to flush any pending writes to the file.. > @@ -393,6 +395,7 @@ void nfs_readahead(struct readahead_control *ractl) > > trace_nfs_aop_readahead(inode, readahead_pos(ractl), nr_pages); > nfs_inc_stats(inode, NFSIOS_VFSREADPAGES); > + task_io_account_read(readahead_length(ractl)); > > ret = -ESTALE; > if (NFS_STALE(inode)) > -- > 2.31.1 > ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-03-14 20:28 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-03-09 18:58 [PATCH 0/1] NFS: Fix read_bytes for buffered reads Dave Wysochanski 2023-03-09 18:58 ` [PATCH 1/1] NFS: Fix /proc/PID/io " Dave Wysochanski 2023-03-14 20:27 ` Daire Byrne
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).